1. Technical Field
This invention relates generally to valves, and more particularly to a safety valve for such applications as closing a natural gas line under earthquake conditions.
2. Background Information
Natural gas usually flows under pressure through somewhat sturdy municipal gas mains to the customer site. Then it flows through a gas meter into customer lines and through those lines to various gas-consuming devices That arrangement presents certain problems, however, for although the gas mains may remain intact during an earthquake, the more vulnerable gas meters, customer lines, and gas-consuming devices often rupture. That poses a significant threat to the community and so we need some way to alleviate the problem.